Clinical trials involving more than 13,000 patients found that those given treatment using the targeted methods, saw disease stalled and tumours shrink at rates far beyond those of standard treatment.

The approach means patients are given treatment based on targeted gene sequencing or using their whole genetic profile.

Personalised medicine is a very, very different way of treating patients. It’s the most exciting thing since chemotherapyRowena Sharpe

The information allows oncologists to select and modify treatment - with estimates that it could mean 7,000 breast cancer sufferers could be spared gruelling chemotherapy every year. Experts said treatment on the basis of DNA tests could become the norm within five years.

The findings, presented at the American Society of Clinical Oncology meeting in Chicago, come from 346 early stage clinical trials which used precision methods.

Cancer medicine has become increasingly personalised, with tests for particular genes, such as the
BRCA1 gene, carried by actress Angelina Jolie Credit:
Umit Bekta/Reuters

Researchers found that tumours in patients who received targeted treatments had shrinkage rates of 30.6 percent, compared with 4.9 percent in those who did not.

Patients given treatment based on specific biomarkers also had a longer time before the disease worsened, with median progression-free survival of 5.7 months compared with 2.95 months for those who were treated with a “blanket” approach.

Rowena Sharpe, head of precision medicine at Cancer Research UK said: “Personalised medicine is a very, very different way of treating patients. It’s the most exciting thing since chemotherapy.”

At the moment it’s more like using a cannonball to kill an antProf Roy Herbst

She said the approach meant that patients could be given the right treatment first, instead of a system of trial and error which means many undergo toxic therapies they may never have needed, instead of the combination they needed.

Prof Roy Herbst, chief of medical oncology at Yale Cancer Centre, said: “This is about finding the right key for the lock. Finding out what it is that is driving the tumour, what makes it tick.

“At the moment it is informed guesswork, so that treatment often doesn’t work for large numbers of patients.” He said the widespread adoption of the method could radically change medicine.

“I believe the potential is huge,” said Prof Herbst, who said large scale international trials were needed, to ensure the most detailed genetic profiles could be built.

British researchers are about to launch a new trial personalised breast cancer medicine Credit:
Rui Vieira /PA

Prof Herbst said the changes meant that patients could receive the most powerful medicine, while suffering less toxicity.

“At the moment it’s more like using a cannonball to kill an ant,” he said.

The leading oncologist said that within five years, patients could be offered “upfront” genetic profiling, so that tailored treatment could be offered without even the delay of tests.

The landmark study by the University of California-San Diego School of Medicine’s Center for Personalized Cancer Therapy was hailed by experts from across the globe as showing that such approaches were "the future" for cancer care.

British researchers are about to launch a new trial personalised breast cancer medicine which could see 7,000 women a year spared chemotherapy, while saving the NHS £17m annually.

The study by University College London, Cambridge University and Cancer Research UK will mean all women will undergo a genetic test of tumour as soon as diagnosed, with results due in 2020. Such tests currently cost around £2,000 – around half the cost of a £4,000 course of chemotherapy.

Baroness Delyth Morgan, chief executive at Breast Cancer Now, said: "This comprehensive study shows that by using biomarkers to match up a tumour’s key features with the most suitable treatments, patients can see real benefit from new drugs at an earlier stage.

“Personalised medicine represents the future of cancer treatment. Everyone’s breast cancer is different, and the better we can target drugs to the exact make-up of a patient’s tumour, the more effective we will be in stopping this dreadful disease.”